What is a Diamond Certification

Established in 1931, the Gemological Institute of America, or GIA, is the world’s foremost authority on diamonds, colored stones, and pearls. It is dedicated to research and education in the field of gemology.


Through the development and dissemination of its policies, the GIA attempts to protect all purchasers of gemstones, by providing the education, laboratory services, research, and instruments needed to accurately and objectively determine gemstone quality.

 

Diamond Education - Understanding the GIA Diamond Certificate


One of the GIA’s more visible services is provided through its GIA Laboratory which provides diamond grading services to describe the characteristics of loose diamonds. The most comprehensive report issued by the GIA for fancy color diamonds is the GIA Colored Diamond Grading Report . This report is considered an important tool in guaranteeing that a diamond is accurately represented to a potential buyer.


The GIA Colored Diamond Grading Report (see copy below), issued for natural colored diamonds weighing 0.15 carats or more, provides a full quality assessment of a colored diamond and contains the following data:

  • Date (of report)
  • Report Number
  • Laser Inscription Registry (if requested)
  • Shape and Cutting Style
  • Measurements
  • Color Origin (natural or treated),
  • Color Grade (hue and fancy color grade),
  • Color Distribution (evenness of color)
  • Clarity Guide (according to the GIA Clarity Scale)
  • Finish (quality of surface condition as well as information re the facets)
  • Polish (overall condition of surface)
  • Symmetry (exactness of diamond’s outline as well as further information re the facets)
  • Fluorescence (strength and color of diamond)
  • Plotting Diagram (approximates shape and cutting style of stone)
  •  Key to Symbols, GIA Clarity Scale, GIA Colored Diamond Scale, Proportion Diagram, and Security Features (of report to ensure authenticity). As an optional service, a full color image of the diamond may also be included.

 

Learn how to read a GIA certificate through Leibish & Co.'s "The GIA Colored Diamond Grading Report - a User's Guide"
 

 

Colored Diamond Grading Report

Colored diamond Grading report

 

 

 

The GIA also offers the GIA Colored Diamond Identification and Origin Report (A.K.A "Color Only" certificate) that describes the color grade and the Origin of a colored diamond and contains the following data:

  • Date (of report)
  • Report Number
  • Laser Inscription Registry (if requested)
  • Shape and Cutting Style
  • Measurements
  • Color Origin (natural or treated)
  • Color Grade (hue and fancy color grade)
  • Color Distribution (evenness of color).

 

 

Colored Diamond Identification and Origin Report

GIA Colored Diamond Identification and Origin Report (A.K.A Color Only report)

 

 

 

Please note that GIA only recently began allowing one to verify a "GIA Colored Diamond Identification and Origin Report" (Color Only report) in the GIA website, here. This This service is currently available for all GIA Grading reports issued after January 1, 2000. If the report is dated after July 1, 2010, a PDF version of the report is available to view or download.

The GIA Colored Diamond Grading Reports are not issued for synthetics, simulants, mounted diamonds or those that have undergone unstable treatments, such as fracture-filling or coating. Any evidence of other treatment is prominently disclosed in the report.


The GIA color grading system for colored diamonds is used worldwide and has been applied to many of the most famous colored diamonds, including the Blue Hope, the Dresden Green, and the Hancock Red.


When a diamond is inscribed with the report number, this provides irrefutable and eternal evidence that the diamond purchased is the diamond documented in the report. This not only assures security when purchasing a fancy color diamond but is a major selling point when wanting to sell that same diamond.


The GIA’s imprimatur, as certified by an accompanying GIA Colored Diamond Grading Report, ensures that a decision to invest in a fancy color diamond can be made with peace of mind. The foremost experts in the world have assessed the relevant diamond on an objective basis and determined its characteristics. This is achieved in a transparent and homogeneous manner in the best equipped laboratories, allowing confidence when purchasing a diamond. 

 

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GIA Report check - a User's Guide (Part 1)
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The GIA Colored Diamond Grading Report - a User's Guide (Part 2)
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The GIA Colored Diamond Grading Report - a User's Guide (Part 3)
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